Video teleconferencing is well known in the art as a means for allowing remote parties to participate in a conversation. Voice, video, and optionally other data are transmitted between parties over a communication network, such as the Internet. The parties are able to see, speak to, and hear the other parties, as well as share other data such as a slide presentation.
Being able to conduct video communication on a mobile device is relatively new development in the art. So called 3G video telephony service based on the ITU H.324M standard is the best known practice in the field. This technology leverages 64 kbps circuit-switched transmission channel to send and receive compressed digital audio visual signals. Due to the inherent limitation of channel bandwidth and processing power available on 3G mobile handsets, the technology suffers from poor audio and video quality which has prevented the service from being widely adopted.
More recent efforts have focused on delivering mobile video communications over packet-switched mobile networks. IMS (Integrated Multimedia Subsystem) is a technology originally devised by the wireless standards body 3GPP in an effort to unify the signaling and transmission of multimedia data including audio and video over the IP (Internet Protocol) layer which in turn can be supported on a variety of lower layer networks such as GPRS, Wireless LAN, CDMA 2000, and fixed line. There has been limited deployment of IMS capable mobile networks and still fewer video communication service offerings that leverage on IMS. AT&T Video Share offers one-way video transmission between two Video Share capable handsets and is powered by IMS, while relying on the regular cellular voice channel for the audio portion of the communication.